Rubbing machine



April 24, 1956 D. E. JONES RUBBING MACHINE Filed March 8, 1954 IN V ENTOR.

flozgZcw 2.170% BY United States Patent RUBBING MACHINE Douglas E.Jones, Menominee, Mich., assignor to Peninsula Tool Company, Menominee,Mich., a corporation (If-Michigan Application March 8, 1954, Serial No.414,785

8 Claims. (Cl. 51-170) This inventionrelates torubbing machines and ismore particularly concerned withimprovements in small portable devicesof this character which have a power driven oscillating shoe adapted tocarry a rubbing element for sanding, bufling, polishing or otherwisefinishing a surface.

It is a general object of the invention to provide a relatively small,portable, power driven rubbing machine, which is rugged in constructionand will withstand hard usage, which is highly efficient in operation,and which may be economically manufactured.

It is a further object of the invention to provide in l a portablerubbing machine of the motor driven oscillating shoe type an improvedflexible connection between the shoe and the motor supporting framewhich comprises hollow, open ended, upright'tube formations of flexiblematerial arranged in pairs at opposite ends of the shoe, each pair oftube formations being connected to the shoe by a generally 'U-shapedbracket having its leg portions extending upwardly from the shoe betweenthe tube formations and attached to the upright Walls of the latter attangential points, the tube formations being attached at opposite pointson the upright walls thereof to depending portions of the motorsupporting frame.

These and other objects and advantages of the invention will be apparentfrom a consideration of the rubbing machine which is shown by way ofillustration in the accompanying drawings, wherein:

Fig. 1 is a side elevation of a power driven rubbing machine embodyingthe principles of the invention, the lower portion thereof being brokenaway to show the mechanism in longitudinal section;

Fig. 2 is a section taken generally on the line 2-2 of Fig. l; and

Fig. 3 is a partial perspective of one end of the machine showing theflexible tubular connecting members between the rubbing shoe and themotor housing.

Referring to the drawings there is illustrated a motor driven mechanismwhich is constructed in accordance with the principles of the invention.The details of the motor are not illustrated and are immaterial to theinvention, it being understood that an electric motor, an air motor orany similar type of power means may be employed for providing power inthe drive shaft of the machine.

The illustrated machine comprises a frame consisting of a motor housing10 and a downwardly opening extension thereon which forms a pad or shoesupporting casing section 11. The motor housing 10 and the casing 11 areconveniently formed as a single integral casing, as shown.

The driving motor (not shown) is supported in the housing 10 andprovides a downwardly projecting power shaft '13 which extendsdownwardly into the casing section 11 and is supported in the bearingmember 14 which is mounted in the recessed aperture 15 in the crosssupport 16, the latter being secured to the bottom of the housing 10 andprojecting into the casing section 11. A fan 17 is secured on the powershaft 13 above the 'casing 11 and provides for circulation of airthrough slots (not shown) in the housing 10.

The housing 10 is provided with a laterally or rearwardly extendinghandle formation 18 which provides a means fortheoperator to grasp themachine in one hand. The handle 18 also accommodates a current supplyingcord and a controlling switch (not shown). A knob 19 is mounted on theforward portion of the casing to provide a means for grasping the toolwith the other hand and for holding the tool against the work.

A rubbing pad or shoe 20 supports the rubbing element 21 which maybe anabrasive coated sheet, as illustrated, or any other element suitable forengaging the work surface to be treated. The rubbing shoe 2%) comprises.a rigid backing plate member 22 and a pad-like member 23 of rubber,felt or similar resilient material. The pad '23 accommodates on itslower face the abrasive element 21.

The rubbing shoe 20 is connected in spaced relation to the downwardlyopening casing 11 by means of flexible connecting members 24, 25 and 26,27 which are arranged in paired relation at opposite ends of the casing11. The members 24, 25,26 and '27 are identical in construction beingcharacterized by a relatively short length of flexible tubing of rubberor fabric reinforced rubber. The wall thickness is sufiicient towithstand the oscillating or rolling action to which these members aresubjected in use. The connecting members 24 and 25 are arranged inlaterally spaced relation at one end of the machine and secured relativeto the rigid backing plate 22, by means of "an upright, U-shaped bracket28 which has its bight portion 29 secured to the upper face of thebacking plate 22 by screw fasteners 30. The members 24 and 25 arearranged with opposed side walls attached to the upwardly extending legs31 and 32 of the bracket 28 by means of bolt or screw fasteners 33 and34, which are provided with suitable elongate clamping Washers 35 and36, to hold the members 24 and 25 in proper vertical alignment. At theiropposite sides the members 24 and 25 are attached to the vertical sidewalls 37 and 38 of the casing 11 by means of bolt or screw fasteners 39and 40 which extend through the oppositely disposed side walls of themembers and which are provided with suitable vertically extendingelongate nut forming clamp plates 41 and 42. The pair of members 26 and27 at the opposite end of the casing 11 are attached to the plate 22 bymeans of a bracket 28', which is identical with the bracket 28, and tothe casing Walls 37 and 38 in the same manner as members 24 and 25. Allof the connecting members 24, 25, '26 and 27 are compressed into an ovalcross section in their normal position as shown in'Fig. 2 to permit theplate 22 to move relative to the casing 11 in an orbitual path, themovement being limited in accordance with the flexibility of themembers.

The lower end of the driven shaft 13 is secured in a recess 43 in theupper face of an eccentric 4 A recess 45 in the lower face of theeccentric 4-4 receives a bearing 46 which is secured on a short postmember 47 attached to the center of the backing plate 22 by a screw orbolt fastener 48. The vertical axes of the drive shaft 13 and the post47 are, of course, offset to give an eccentric motion to the shoe 20when the eccentric 44 is rotated by operation of the shaft 13. Theeccentric 44 is provided with a counterweight arm 49 which reduces thevibration in the device.

The rubbing shoe 20 is preferably provided at its ends with clampingmeans for securing in position thereon the abrasive coated sheet 21. Theillustrated securing means comprises a cross shaft member 50 of squarecross section arranged adjacent each end of the plate 22. The crossshaft members 59 are identical and are secured in the same manner to theplate 22. The members 50 are formed at the ends with cylindrical bearingsections 51, 51 which are held in rotatable relation beneath the curvedends 52, 52' of spring retainer plates 53, 53 which are secured by screwor rivet fasteners 54, 54. The ends of the members 50 may be slotted toreceive a screw driver or other tool for rotating the same in frictionalengagement with the turned over ends of the abrasive sheet 21 to securethe same in clamping relation on the top of the plate.

While specific materials and particular details of construction havebeen referred to in describing the invention it will be understood thatother materials and variations in the details of construction may beresorted to within the spirit of the invention.

I claim:

I. in a rubbing machine having a rubbing shoe, a supporting housing anda power driven shaft extending into said housing, an eccentricconnection between the driven shaft and the center portion of the shoefor oscillating the shoe relative to the housing, a plurality offlexible, tubular connecting members between the housing and marginalportions of the shoe, which connecting members are arranged inoppositely disposed relation adjacent the periphery of the housing withthe long axis thereof generally parallel to the power driven shaft, andmeans for securing opposite side wall portions of each of saidconnecting members to the shoe and to an adjacent portion of saidhousing.

2. In a rubbing machine having a vibratable shoe, a supporting housingand a power driven shaft extending into said housing, an eccentricconnection between the driven shaft and the shoe for vibrating the shoe,a plu rality of flexible, tubular connecting members between the housingand marginal portions of the shoe, which connecting members are arrangedin paired relation at opposite sides of the housing adjacent theperiphery of the housing and with the long axis thereof generallyperpendicular to the plane of the shoe, means for securing side wallportions of each of said connecting members to an adjacent portion ofsaid housing, and bracket means for securing opposed side wall portionsof said connecting members to said shoe.

3. In a rubbing machine having an oscillatable shoe, a supportinghousing having oppositely disposed side walls and a power driven shaftextending into said housing, an eccentric connection between the drivenshaft and the shoe for oscillating the shoe, a plurality of hollow,flexible cylindrical connecting members between the side walls of thehousing and marginal portions of the shoe, which connecting members arearranged in opposed and paired relation, means for securing side wallportions of each of said connecting members against adjacent side wallportions of said housing, a bracket member projecting upwardly of saidshoe between the connecting members of each pair thereof, and means forsecuring opposite side wall portions of said connecting members to saidbracket.

4. A rubbing machine comprising a housing having side wall membersframing an open end, a rubbing shoe positioned over the open end inspaced relation thereto, a power driven shaft extending in said housingand terminating short of said shoe. :1 fixed shaft extending from saidshoe into said housing in offset relation to said power driven shaft, acounterweightecl eccentric connecting said shafts whereby said shoe isvibrated upon rotation of said power driven shaft, independent flexibleconnections between marginal portions of said shoc and the side wallmembers of said housing adjacent said opening for limiting thevibrational movement of said shoe, said flexible connections comprisingperipherally spaced hollow tube-like sections of resilient materialarranged with the long axis thereof normal to the surface of the rubbingshoe, fastener members connecting side wall portions of said tube-likesections to the internal surfaces of the side wall members of saidhousing and angular bracket members connecting opposite side wallportions of said tube-like sections to said shoe.

5. A rubbing machine comprising a housing having side wall membersframing an open end, a rubbing shoe having a rigid backing platepositioned over the open end in spaced relation thereto, a power drivenshaft extending in said housing and terminating short of said backingplate, a fixed shaft extending from said backing plate into said housingwith the long axis thereof in offset relation to the axis of rotation ofsaid power driven shaft, a counterweighted eccentric connecting the endsof said shafts whereby said shoe is vibrated upon rotation of said powerdriven shaft, independent flexible connections between peripheralportions of said backing plate and the side wall members of said housingadjacent said opening for limiting the vibrating movement of said shoe,said flexible connections comprising peripherally spaced tubularsections of rubber-like resilient material arranged with the long axisthereof normal to the surface of the rubbing shoe, fastener membersconnecting side wall portions of said tubular sections to the internalsurfaces of the side wall members of said housing and angular bracketmembers connecting opposite side wall portions of said tube-likesections to said shoe, with said tubular sections being normallycompressed in the transverse direction.

6. A rubbing machine comprising a housing having side wall membersframing an open end, a rubbing shoe positioned over the open end inspaced relation thereto, a power driven shaft extending in said housingand terminating short of said shoe, a fixed shaft extending from saidshoe into said housing in olfset relation to said power driven shaft, acounterweighted eccentric connecting said shafts whereby said shoe isvibrated upon rotation of said power driven shaft, independent flexiblemembers spaced outwardly of said eccentric and connecting said shoe withthe side wall members of said housing adjacent said opening for limitingthe vibrational movement of said shoe, said flexible members comprisingperipherally spaced hollow tube sections of rubber-like resilientmaterial arranged with the long axis thereof normal to the surface ofthe rubbing shoe, fastener members connecting side wall portions of saidtube sections to the .internal surfaces of the side wall members of saidhousing and angular bracket members connecting opposite side wallportions of said tube sections to said shoe, said tube sections beingcompressed between the angular bracket members and the side wall membersof said housing.

7. A rubbing machine comprising a housing having side wall membersframing an open end, a rubbing shoe positioned over the open end inspaced relation thereto, a power driven shaft extending in said housingand terminating short of said shoe, a fixed shaft extending from saidshoe into said housing in offset relation to said power driven shaft, 9.counterweighted eccentric connecting said shafts whereby said shoe isvibrated upon rotation of said power driven shaft, independent flexibleconnections between marginal portions of said shoe and the side wallmembers of said housing adjacent said opening for limiting thevibrational movement of said shoe, said flexible connections comprisingperipherally spaced tube sections of rubber hose material arranged inpairs at opposite ends of said casing, fastener members connecting sidewall portions of said tube sections to the internal surfaces of the sidewall members of said housing and U- shaped bracket members connectingthe opposite side wall portions of pairs of said tube sections to saidshoe.

8. In a rubbing machine having an oscillating rubbing shoe, a supportinghousing having peripheral side walls and a power driven shaft extendinginto said housing,v an eccentric connection between the driven shaft andthe shoe for oscillating the shoe, a plurality of flexible, tubularconnecting members having side wall portions secured to adjacentperipheral side wall portions of the housing,

and U-shaped bracket members each having the legs thereof secured toopposed side wall portions of a pair of said connecting members andhaving the bight portion thereof secured to an end of said shoe.

References Cited in the file of this patent UNITED STATES PATENTS GeorgeMar. 12, Kehle Mar. 11,

: Kehle Jan. 20, Champayne Jan. 23, Crosby Mar. 20, Happe Aug. 12,

' Atkin May 26, Champayne Feb. 23,

